Biopolymers as chitosan which is one of the emerging sorption material for the removal of
metal ions was applied to determine germanium(IV), even at low concentrations. A selective,
sensitive and rapid method was described for preconcentrative determination of Ge(IV) using
the synthesized 2-amino-4-(m-tolyazo)pyridine-3-ol (ATAP), which was chemically immobilized
on chitosan. The sorbent synthesized material was selective to Ge(IV) within a best response time
of 10 min. The procedure was selective in presence of other diverse anions and cations. Under
the optimum experimental conditions, calibration plots were linear over the concentration range
of 2.5 to 75 ng mL−1 of Ge(IV). The obtained results are 100 times lower than by the direct
determination of Ge(IV) by FAAS. The developed method is repeatable with a relative standard
deviation of 2.55%. The developed sorbent was applied successfully to determine Ge(IV) in
environmental samples. Unlike most preconcentration methods, the present enrichment work
allowed for a rapid and reliable determination of Ge(IV) in real water and soil samples by the simple, rapid and routinely available spectrophotometric technique